On the same day General Motors and Japan's SoftBank announced a massive $3.35 billion investment in GM's Cruise self-driving-car division, Waymo and Fiat Chrysler Automobiles revealed an expansion of their partnership — and dangled an intriguing new business option.

FCA plans to supply Waymo's autonomous fleet with 62,000 Chrysler Pacifica minivans, a big leap from the 600 vehicles Waymo is now operating. According to the companies, deployment will commence later this year.

"FCA is committed to bringing self-driving technology to our customers in a manner that is safe, efficient, and realistic," FCA CEO Sergio Marchionne said in a statement. "Strategic partnerships, such as the one we have with Waymo, will help to drive innovative technology to the forefront."

Marchionne is a recent and rapid convert to autonomous tech, where until the Waymo partnership emerged in 2017 the carmaker was seen as lagging peers such as GM and Ford. The CEO — who oversaw the merger of Fiat and Chrysler during the financial crisis in 2009 when Chrysler was bailed out by the federal government and entered bankruptcy — will retire in 2019.

In combination with Waymo, FCA hasn't just been playing catch-up; the automaker has surged into a leading role.

"Currently, Waymo is the only company with a fleet of fully self-driving cars, with no one in the driver seat, on public roads," the companies said in a joint statement. "Later this year, Waymo will launch the world's first self-driving transportation service, allowing the public to use Waymo's app to request a vehicle."

John Krafcik, Waymo's CEO, added: "We're excited to deepen our relationship with FCA that will support the launch of our driverless service, and explore future products that support Waymo's mission."

The self-driving-car race is heating up

Waymo CEO John Krafcik. AP

Waymo used to be referred to as the Google Car Project, until the division was spun off in late 2016. It has been pursuing autonomous technologies since 2009, but only recently has Krafcik begun to offer insight in how the company will build businesses around its approach.

FCA is a prominent auto-industry partner, providing a versatile minivan that can transport small groups of riders. Around the time of the New York auto show this year, Waymo announced that it would add Jaguar Land Rover as a partner, using the forthcoming Jaguar I-Pace as a luxury platform for what Waymo calls its autonomous "driver."

Thus far, fully autonomous technologies have been discussed in the context of ride-hailing or -sharing services, in which the tech and the vehicles can be "geo-fenced," or confined to specific areas that can be mapped with a high level of accuracy.

On Thursday, however, FCA and Waymo dangled the possibility of Waymo technology being licensed for use in FCA vehicles available for consumers to obtain. That would represent a significant leap into the existing car business, where self-driving systems such as Tesla's Autopilot and GM's Cadillac Super Cruise are effectively very advanced forms of cruise control.

Waymo has stressed the breadth of what the technology can achieve, ranging from models now being developed to a future in which the systems provide shipping and logistics services and augment public transportation.

Multiple approaches to a rapidly evolving business opportunity

Waymo and FCA are taking different approaches to autonomy than GM Cruise is, though both sides have bet on laser radar, or lidar, as the best technology for fully self-driving cars. (Tesla Autopilot, by contrast, uses a system of cameras and sensors, avoiding the more expensive lidar units.)

GM maintains that software and hardware have to be integrated at the level of manufacturing to achieve successful autonomy and to scale the business opportunities. Waymo, not being a huge manufacturer of automobiles, has concentrated on developing a "driver" that can be installed in a variety of vehicles.

Both approaches could work out, but what's clear is that as the race to create fully self-driving vehicles intensifies, the rubber is finally starting to seriously hit the road.